The 14-gram scarlet-chested sunbird (Chalcomitra senegalensis) stands approximately 15 cm tall. The male’s feathers are all black, but the crown and chin have an iridescent emerald green color. The upper chest and throat are red. The bill, foot, and legs are all black. Brown eyes are present.
The physical characteristics of the male Chalcomitra senegalensis differ slightly from those of the female.
The female Scarlet-chested sunbird can be distinguished from the female African Black sunbird by their plumage, which is greyish olive above and severely mottled underneath.